Portable Information Device

1. A portable information device, comprising: a first chassis having a first display; a second chassis having a second display; a hinge mechanism rotatably couples said first chassis to said second chassis, wherein said hinge mechanism includes: a plurality of hinge shafts with axial directions provided along an aligning direction of said first and second chassis; a slide support part, to be slidable along said aligning direction, is connected to one of said hinge shafts closest to said first chassis in a manner to be relatively rotatable; and a fixed support part, fixed to said second chassis, is connected to one of said hinge shafts closest to said second chassis in a manner to be relatively rotatable; wherein said hinge mechanism allows said first and second chassis to change between a flat-plate form in which said first and second displays are arranged side-by-side, and a folded form in which said first and second displays face each other.

2. The portable information device of claim 1 , wherein, in said flat-plate form, said hinge mechanism is placed in a position where said hinge shafts overlap said chassis, while in said folded form, at least one of said hinge shafts is placed in a position to be exposed from a gap formed between edges of said first and second chassis.

3. The portable information device of claim 1 , wherein the number of said hinge shafts is four.

4. The portable information device of claim 1 , wherein said slide support part is connected to said first chassis via an elastic member, and said fixed support part is directly connected to said second chassis without any elastic member.

5. A portable information device, comprising: a first chassis having a first display; a second chassis having a second display, wherein said first and second chassis have planes on end faces of edges of said first and second chassis; a hinge mechanism rotatably couples said first chassis to said second chassis, wherein said hinge mechanism includes: a plurality of hinge shafts with axial directions provided along an aligning direction of said first and second chassis; a slide support part, to be slidable along said aligning direction, is connected to one of said hinge shafts closest to said first chassis in a manner to be relatively rotatable; and a fixed support part, fixed to said second chassis, is connected to one of said hinge shafts closest to said second chassis in a manner to be relatively rotatable; wherein said hinge mechanism allows said first and second chassis to change between a flat-plate form in which said first and second displays are arranged side-by-side, and a folded form in which said first and second displays face each other.

6. The portable information device of claim 5 , wherein, in said flat-plate form, said planes of said end faces of said first and second chassis abut each other.

7. The portable information device of claim 5 , wherein the number of said hinge shafts is four.

8. The portable information device of claim 5 , wherein said slide support part is connected to said first chassis via an elastic member, and said fixed support part is directly connected to said second chassis without any elastic member.

9. A portable information device, comprising: a first chassis having a first display; a second chassis having a second display; a hinge mechanism rotatably couples said first chassis to said second chassis, wherein said hinge mechanism includes: a plurality of hinge shafts with axial directions provided along an aligning direction of said first and second chassis; a slide support part, to be slidable along said aligning direction, is connected to one of said hinge shafts closest to said first chassis in a manner to be relatively rotatable, wherein said slide support part includes a bracket fixed to said first chassis and a slide member supported to be slidable with respect to said bracket; and a fixed support part, fixed to said second chassis, is connected to one of said hinge shafts closest to said second chassis in a manner to be relatively rotatable; wherein said hinge mechanism allows said first and second chassis to change between a flat-plate form in which said first and second displays are arranged side-by-side, and a folded form in which said first and second displays face each other.

10. The portable information device of claim 9 , wherein, in said flat-plate form, said slide member is placed at a first position moved in a direction to be separated from said second chassis, while in said folded form, said slide member is placed at a second position moved in a direction to come close to said second chassis.

11. The portable information device of claim 10 , wherein said slide support part further includes a first retaining unit that retains said slide member at said first position, and a second retaining unit that retains said slide member at said second position.

12. The portable information device of claim 11 , wherein said first retaining unit includes a latch part and a first engaging portion for engaging said latch part at said first position, said second retaining unit includes said latch part and a second engaging portion for engaging said latch part at said second position, and said latch part is in either one of said slide member and said bracket, and said first engaging portion and said second engaging portion are provided in said other of said slide member and said bracket.

13. The portable information device of claim 11 , wherein said first retaining unit includes a magnet that shows attraction between said slide member and said bracket when said slide member is at said first position.

14. The portable information device of claim 9 , wherein said slide support part is also connected to said first chassis via an elastic member, and said fixed support part is directly connected to said second chassis without any elastic member.

15. The portable information device of claim 9 , wherein said bracket is a plate member, and one surface of said plate member becomes a supporting surface of said slide member and is arranged to face inner surfaces of said chassis, and said other surface thereof is arranged to face bottom surfaces of said first and second displays.

16. The portable information device of claim 9 , wherein the number of said hinge shafts is four.